In the past, many work holders have been provided for holding doors, panels and other relatively thin unwieldy objects in an upright position to facilitate trimming the edges, insetting locks and hinge plates and performing other work associated with hanging the door in a frame or the like. In earlier door holders, a base was provided with upstanding clamp members and at least one of such clamp members was slidably moved by hand relative to the other to clamp and release the workpiece. Some examples of this type of structure are shown by the U.S. Pat. Nos. to Smith 611,340; Lucabaugh 708,238; Adams 849,354; Lynch 1,067,667; and Hinds 1,606,634. In later door and other work holders, a base was provided with one or more swingable or sliding clamping members associated with a workpiece support so that when the workpiece was placed on the support, the weight of the workpiece caused the clamping members to move into engagement therewith. This type of structure is disclosed in the U.S. Pat. Nos. to Tracy 2,605,795; and LaRouche 2,830,632. Also, the U.S. Pat. No. 4,054,280 to Alberts discloses a clamping member which engages a workpiece by fluid pressure and U.S. Pat. No. 2,471,103 to Franks et al discloses a work holder which holds a relatively small workpiece by spring pressure.